Starter Solenoid Sticking - Ford 1210

[Stumpi]

Hello, I've just replaced the starter solenoid on my Ford 1210. The old one was worn out and would take many tries before it would close the contacts and turn the starter motor. The new one works every time on the first try except the starter continues to run once you release the key.

The only way to shut it off is to pull the negative battery cable, smacking the solenoid with a hammer doesn't seem to help. Once the negative lead is reconnected it doesn't try and start again so it doesn't seem to be welding the contacts. The bendix drive moves freely and I can't feel any hangups on the linkage. I tried letting it start and then shutting it down and when I did the starter had stopped so it seems to only remain stuck as long as the starter is under load. It also starts and stops normally when tested on the bench.

I'm wary of just blindly replacing parts here, I've read too many other threads of people replacing the whole starter motor, battery leads, and ignition switch and still having this problem. I'd suspect the starter except it doesn't stick with the old solenoid. Anyone been down this road before or have any ideas I could try?

 

[skyhook]

Check the condition of your battery, cables etc. I recently installed a new starter on my machine ( what a pain that was ) and it did exactly that. Not always but as you stated, only when the battery was weak. I ended up installing a " dead switch " to disconnect the battery in case of this happening. I've had to use it a few times, much better than getting out and disconnecting the battery. Had the old starter rebuilt and will replace the new one this summer. I also installed a battery tender and it keeps the battery topped up and haven't had any issues since. So this is why I think it could be a battery issue. Hope you installed the return spring on the solenoid. Your starter could also be all gummed up inside like my old one was. Good luck.

 

[Stumpi]

Battery is 900CCA, has been on a tender, and is fairly new so I'm confident it's not the problem. I've measure the resistance of both cables and came up with less than 0.5 ohms on both. I should probably measure the voltage drop while cranking but I think the cables are ok.

The return spring is captive on this solenoid. Can't be removed without uncrimping the solenoid housing from the terminal cap. That said the return spring on the new one is slightly weaker than the old solenoid. Since it releases once the load has been taken off the starter motor my current theory is either the return spring is too weak or the striker which is supposed to pop the contacts open isn't getting pulled back far enough to do it's job (to weak\too strong solenoid, not enough travel, bad spring selection, ect).

 

[Stumpi]

Measured the voltage drop while cranking. Got 0.2V on the positive lead, 0.4V on the neg. Had 10.8V at the battery while cranking and 10.2 between the solenoid terminal and starter body. Everything seems happy there.

I tried bypassing the ignition switch by shorting the solenoid lead to the solenoid terminal with 14 gauge wire. No difference.

Starter is clean and free. Might be a little wear in the end bushing but doesn't feel like more than about .010" of run out.

Tried flipping the solenoid over and reversing the terminals. Solenoid just shorted to ground, wouldn't actuate.

Anybody got anything else? I'm to the point of trying a new solenoid but I don't have much faith it's going to work.

 

[skyhook]

If it were me, I'd replace the whole starter and be done with it. Their around a hundred bucks.

 

[Texasmark]

The solenoid is a high current switch activated by a low current control circuit switched on by the ignition switch in the start position.

The high current portion, ⅜" terminal to terminal has large copper connectors inside the unit. Applying current from the ignition switch in the start position pulls a copper disc mounted on a steel rod (magnetic) down and forces contact between it and the two studs providing a high current path for power to the starter.

The starter can't turn if that switch is open. If you think it's open but it's not, the starter will spin till you open the conducting path as you found out.

You have to determine if your start switch applies and removes power when it it's supposed to and ensure that the plunger spring forces the plunger back up to open the high current contacts when the start switch is released.

Your 1210 isn't all that big so I don't see you "welding" new contacts on your replacement solenoid by excessive starting current since you said that the starter works fine when told to start the engine.

One thing to check is the starting (contact closing) voltage on the solenoid. If you don't have a voltmeter use a 12v lamp and some hookup wire connecting the lamp between the small input terminal of the solenoid and battery -.

Disconnect one of the high current leads to the solenoid so the starter won't spin. Put the meter or bulb on the input small terminal which gets voltage from the ignition switch. Operate the switch to the start position and back several times observing that voltage appears at that terminal or the lamp attached glows only when the ignition switch is in the start position. Also listen for the solenoid "click" which indicates that the center disc is being pulled down to close the circuit between the two large terminals.

If you don't hear the click and the voltage goes away when the start switch is released you have a defective new solenoid. If the voltage stays at the solenoid small terminal when you release the start switch, you need a new ignition switch.

 

[mitch becton]

if you consider a new starter there is a gear reducted starter for it through dbelectrical part number 110399 it sells for 103.00 free delivery this would be much better and about twice amount of cranking power past history tell me not to attempt to repair the old style starter very hard sometimes to make work properly good luck also this looks nothing like your starter but it works well have sold over the years

 

[ovrszd]

I recently bought a new starter/solenoid combination for my Ford. Same reason you are working on yours. First time I used the new system it wouldn't quit turning and I had to remove batter cable to stop it. Took solenoid off starter. Cleaned barrel that solenoid plunger moves in. Lubed it with a film of light oil. works like a champ.

 

[Texasmark]

if you consider a new starter there is a gear reducted starter for it through dbelectrical part number 110399 it sells for 103.00 free delivery this would be much better and about twice amount of cranking power past history tell me not to attempt to repair the old style starter very hard sometimes to make work properly good luck also this looks nothing like your starter but it works well have sold over the years

I just bought a voltage regulator from dbelectrical.com. Great product, great price, and super fast shipping. It's installed and working fine in my 3000.

 

[Texasmark]

I recently bought a new starter/solenoid combination for my Ford. Same reason you are working on yours. First time I used the new system it wouldn't quit turning and I had to remove batter cable to stop it. Took solenoid off starter. Cleaned barrel that solenoid plunger moves in. Lubed it with a film of light oil. works like a champ.

Glad you tossed in that tip. My comment was directed at the separate solenoid where no external mechanical devices/connections are used.